Randomized, placebo-controlled, parallel-group, double-blind, multiple-dose, activity and safety clinical study of SRT2104 administered orally once daily for 28 consecutive days. This will be an inpatient/outpatient study to assess the safety and pharmacokinetics of SRT2104 in type 2 diabetic male and female subjects on an existing, stable, background metformin therapy. Approximately 80 subjects will be enrolled. Subjects will be evenly randomized to receive SRT2104 2.0 g/day or placebo in the fed state.